Primordial black hole versus inflaton

TL;DR

This paper compares dark matter production via primordial black holes and inflaton decay during reheating, analyzing how different initial conditions and parameters influence viable dark matter mass ranges.

Contribution

It provides a detailed comparison of dark matter production mechanisms from PBHs and inflaton decay, highlighting the impact of initial conditions and model parameters on dark matter viability.

Findings

Large range of dark matter masses viable with PBH-controlled reheating

Inflaton-dominated reheating broadens dark matter possibilities

Dependence of dark matter production on initial PBH mass and population

Abstract

We compare the dark matter(DM) production processes and its parameters space in the background of reheating obtained from two chief systems in the early Universe: the inflaton $\phi$ and the primordial black holes (PBHs). We concentrated on the mechanism where DMs are universally produced only from the PBH decay and the generation of the standard model plasma from both inflton and PBHs. Whereas the distribution of Primordial Black Holes behaves like dust, the inflaton phenomenology depends strongly on its equation of state after the inflationary phase, which in turn is conditioned by the nature of the potential $V(\phi)$. Depending upon the initial mass and population of PBHs, a large range of DM mass is shown to be viable if reheating is controlled by PBHs itself. Inflaton-dominated reheating is observed to further widen such possibilities depending on the initial population of black holes and its mass as well as the coupling of the inflaton to the standard model sector.